The effects of cocaine on scalp EEG and FDG PET scans are being compared to determine the brain areas involved in the cocaine-induced euphoria. In previous studies, cocaine increased EEG beta power. The distribution of cortical areas responsible for the EEG beta increase and the time course of the beta increase have not as yet been determined. The present study was designed to answer these two questions. The complimentary nature of the EEG and PET data will delineate the anatomical and electrophysiologic mechanisms involved in cocaine induced euphoria. Twenty subjects were tested using EEG measures with placebo, 20mg and 40mg of cocaine in double blind order in previous years and seven additional subjects were tested during the current year. EEG beta increased in dose dependent manner starting immediately after the injection and continuing for twenty minutes. The increase in EEG beta was maximal in frontal cortical areas. The relationship between the increase in beta and subjective state is currently being investigated.